u could have buried them. This is a big territory. We haven't been
able to search every square foot of it."

"Ryan, it was thirty or forty below zero last night. How the devil could
I dig holes in this ground to bury anything?"

"At forty below, how could your bacteria function to rot them away?"

Ekstrohm could see he was facing prejudice. There was no need to keep
talking, and no use in it. Still, some reflex made him continue to
frame reasonable answers.

"I don't know what bacteria on _this_ planet can do. Besides, that was
only _one_ example of a natural phenomenon."

"Look, Ekstrohm, you don't have anything to worry about if you're not
responsible. We're going to give you a fair test."

What kind of a test would it be? He wondered. And how fair?

Nogol came trotting up lightly.

"Ryan, I found some more wart-hogs and they keeled over as soon as they
saw me."

"So it _was_ xenophobia," Ekstrohm ventured.

"The important thing," Ryan said, with a sidelong glance at the
surveyor, "is that now we've got what it takes to see if Ekstrohm has
been deliberately sabotaging this expedition."

* * * * *

The body heat of the three men caused the air-conditioner of the tiny
bubble to labor.

"Okay," Ryan breathed. "We've got our eyes on you, Ekstrohm, and the
video circuits are wide open on the dead beasts. All we have to do is
wait."

"We'll have a long wait," Nogol ventured. "With Ekstrohm here, and the
corpses out there, nothing is going to happen."

That would be all the proof they needed, Ekstrohm knew. Negative
results would be positive proof to them. His pink ticket would turn pure
red and he would be grounded for life--_if_ he got off without a
rehabilitation sentence.

But if nothing happened, it wouldn't really prove anything. There was no
way to say that the conditions tonight were identical to the conditions
the previous night. What had swept away those bodies might be comparable
to a flash flood. Something that occurred once a year, or once in a
century.

And perhaps his presence outside _was_ required in some subtle
cause-and-effect relationship.

All this test would prove, if the bodies didn't disappear, was only that
conditions were not identical to conditions under which they did
disappear.

Ryan and Nogol were prepared to accept him, Ekstrohm, as the missing
element, the one ingredient needed to vanish the corpses. But it could
very well be something e